1. Field of the Invention
Embodiments of the present invention generally relate to a method and apparatus for cleaning and/or preparing a surface of a substrate, such as a semiconductor wafer. More specifically, to an apparatus and method of rapidly filling a processing volume of a chamber for cleaning and/or preparing the substrate surface.
2. Description of the Related Art
During the fabrication of semiconductor substrates, multiple cleaning steps are typically required to remove impurities from the surfaces of the substrates before subsequent processing and high levels of cleanliness are generally required during the cleaning of semiconductor substrates. The cleaning of a substrate, also known as surface preparation, typically includes subjecting the substrate to a sequence of chemical treatment and rinse steps and eventually to a final drying step. A typical cleaning/surface preparation procedure may include etch, clean, rinse and dry steps. During a typical cleaning step, the substrates are exposed to a cleaning solution that may include water, ammonia (NH3), hydrofluoric acid (HF) or hydrochloric acid (HCl), and hydrogen peroxide (H2O2). After cleaning, the substrates are rinsed using ultra-pure water, such as de-ionized (DI) water, and then dried using one of several known drying processes.
In some cases, various substrate cleaning/surface preparation processes are advantageously performed using a chamber sized to receive and process a single substrate, or sized to receive and process no more than two substrates at a time. Multiple chambers may be mounted on a tool or platform so that multiple single substrates, or multiple pairs of substrates can be processed at one time. Chemicals and processes may be monitored more efficiently to assure more uniform processing of each substrate, or pair of substrates. The substrate or substrates may be processed in a vertical orientation, wherein the typical processing surface(s) of the substrate(s) face a horizontal direction, as described in U.S. patent application Ser. No. 11/620,610, to Lester, et al., entitled “Wet Clean System Design,” filed Jan. 5, 2007.
The multiple chamber configuration on the platform generally requires a high fluid volume to fill each of the chambers. Typically, at least a portion of the fluids, such as DI water, are supplied by a DI water source located in the manufacturing facility, and the DI water source may not have the capacity to keep up with the fluid demand. For example, each chamber may require between about 35 liters per minute (LPM) to about 45 LPM to fill the volume of each chamber. Additional chambers on the platform, which may be operating in parallel, may increase the fluid demand. Thus, the facility source may not be able to provide the needed flow rate and/or flow pressure to fill the chambers. Further, rapid filling of the chambers may require even higher flow rates and pressures.
What is needed is an apparatus to facilitate rapid filling of the chambers using the facility pressure and flow rate.